Stamp duty tax has hit a record level of £11.7bn, prompting estate agents to urge election candidates to safeguard the property industry as a major source of tax revenue.
The amount of money raised by the government from property transactions has jumped 70 per cent over the last five years, from £6.9bn.
In the past year alone, the tax take has grown by £1.1bn, according to London estate agents Ludlow Thompson. The rise follows a three per cent hike in stamp duty on second homes which came into effect on 1 April last year.
However, estate agents have warned that although the increases in tax may help the government in the short term, "there is no guarantee for the same returns in future".
In particular, the economic uncertainty around Brexit may hurt tax revenues. Property transactions have fallen substantially since the vote, limiting the tax income to the Treasury.
Stephen Ludlow, chairman at Ludlow Thompson, said: "The record high take shows just how dependent the government is becoming on stamp duty land tax.
"Its manifesto needs to have policies in place that will help the property market if they are going to rely so heavily on the take from stamp duty land tax."
Despite the concerns of many in the property industry, the government has shown no signs of budging on stamp duty.
Speaking to the communities committee last week, communities secretary Sajid Javid said that increasing rates of stamp duty on homes worth over £1m had impacted relatively few people.
"My focus has been on people on average incomes trying to buy an average home," he said.